Vertical take-off aircrafts, in particular drones, have advantageous characteristics with regard to targets to be headed for. Thereby, it is of major significance that vertical take-off aircrafts or drones, respectively, do not require a runway or landing strip as they can land or take-off vertically from the ground. With such vertical take-off aircrafts it is further possible to float above a specific target as to thereby carry out observation missions, for example, wherein the floating may also be referred to as hovering. Thereby, the vertical take-off aircrafts may hover above one and the same target multiple minutes, but also multiple hours, as to thereby capture specific objects on ground during the observation mission. A vertical take-off aircraft is a helicopter, for example. During long taking en-route flights, a helicopter is less efficient with regard to aerodynamic lift due to missing wings.